not sure how to fix but i think this is why i cannot add any horses to the granger app

Yes this is the reason of Granger not working, but am not sure how this happened. Does that directory exist?

I've just tested this on WU by doing fresh install and joining random server. Then started WA, set the wurm client path manually to "C:\Program Files (x86)\Steam\steamapps\common\Wurm Unlimited\WurmLauncher\PlayerFiles\" and it found my char and everything worked.